For existing intelligent containers, there is usually an electronic intelligent module featured with a magnetic function, timing, tracking and provides an electronic alarm installed on the upper part of the inner corner post at the door end of the container. The module is disposed in a trough formed by the inner and outer corner posts, its module arm is adhered to the inner corner post. There is a pressure transducer attached to the module, and the transducer has an antenna that cross the space between the door seal and the inner corner post and extends out of the container body. During transportation, the antenna, integrated with the containerized traffic monitoring system, performs timing, tracking and alarm functions for the container by radio signal transmission. Its working principal includes that when the door is normally closed, the sealing joint strip on the door leaf presses on the pressure transducer on the module. However, if the door is illegally opened, the sealing joint strip will be displaced from the pressure transducer with the door movement, and on the basis of pressure being relieved from the transducer, the module will output a signal that the door has been opened illegally. Later on, the module will perform relevant signal processing and output the alarm signal via the antenna, to timely inform the monitoring system staff so that they may adopt appropriate safe precautionary measures.
The existing intelligent containers often have the following problems:
1. The pressure transducer is adopted to perceive the pressure on the door sealing strip and detect whether the door is illegally opened, which is not very reliable. The first factor is that the hardness value of the door sealing strip of the container allows some alteration within a certain field, while different sealing strip products have different pressure within the same space between the door and the doorcase. In particular, the sealing strip on the module will be increasingly aged, and there is an obvious pressure difference between new sealing strips and old ones. The second factor is that, according to some experimental evidences, when the electronic intelligent module is installed onto a new container body and the door where the module is installed is open and is spaced about 50 mm away from the other door, the sealing strip will still press onto the pressure transducer of the module. However, on the basis of the pressure remaining on the sealing strip, the pressure transducer of the module won't output any signal of illegal door opening.
2. The mounting position of the module often allows the pressure transducer to be defeated. According to experimental evidences, if a thin plate or the like is inserted into the space between the sealing strip and the pressure transducer in advance of opening the door, the plate will maintain pressure on the pressure transducer. Thus, the door might be illegally opened, but without triggering the monitoring function of the electronic intelligent module.
3. The mounting position often brings about any sealing failure. The module arm cross the space between the door sealing strip and the inner corner post and lets the antenna extend out of the container body, which may cause the sealing strip to be distorted and fail to press on the doorcase tightly. Under such conditions, all of the weather tightness tests on the container body with the electronic intelligent module installed might fail and bring about water leakage, which often results in the container failing to meet the ISO standards.
4. A suite of intelligent devices can only detect whether a door is illegally opened, while either of the two doors might be independently and illegally opened, so it is required to installed two suites of intelligent devices at an increased cost.
5. The electronic intelligent module is installed onto the container by magnetic force. When the container travels back after being unloaded at some destination, the module is easily lost. That is to say, it is difficult to use the module to manage the container.
Thus, there is inconvenience and defects associated with the use of existing intelligent containers, so it is necessary to make some improvements therein.